Condition based maintenance programs rely upon inspection to identify those parts that are nearing their end of life. Bearings are no exception to this rule. The replacement of a bearing before it is fully worn out may be wasteful, but waiting too long to replace a bearing can be catastrophic in some applications, particularly with rotorcraft and aircraft. It is known in the art to place sensors inside a bearing to measure wear. Discenzo (U.S. Pat. No. 7,551,288) disclosed a system for monitoring bearing wear that employed an optical fiber embedded in the bearing and operatively coupled to an interferometric system. Such a system will measure wear at only one point, and that point may not coincide with the area of maximum wear. Bearings with multiple optical fibers were disclosed to try to remedy this defect, but the overall complexity required for this measurement rendered the solution cost prohibitive.
It is the goal of this invention to provide a sensor that will detect wear in any location within the bearing, and enable timely replacement, using a cost effective method.